There have been conventionally known autonomous mobile bodies, such as autonomous moving-type robots, which are autonomously movable according to information on a surrounding environment in a limited region inside or outside of a building.
Such an autonomous mobile body creates, in a movement region in a prestored environment map, a movement path extending from a current position of the autonomous mobile body to a specific target point. This allows the autonomous mobile body to autonomously move in accordance with the movement path. Therefore, an autonomous mobile body typically has a function of recognizing a self-position in a movement region.
In order for an autonomous mobile body to recognize a self-position, the autonomous mobile body needs to compare an environment map with environment information which is obtained by a sensor provided in the autonomous mobile body. Various methods have been studied for carrying out the comparison.
Note that in a case where the autonomous mobile body recognizes a self-position, an actual environment in which the autonomous mobile body autonomously moves may be inconsistent with the environment map due to factors such as (i) a measurement error in creating the environment map, (ii) an environmental difference between a timing at which the environment map has been created and a timing at which the autonomous mobile body autonomously moves, and/or (iii) presence of a mobile body, such as a human, other than the autonomous mobile body itself. According to a conventional autonomous mobile body, it may not be possible to properly correct a self-position due to such an inconsistency.
Examples of known techniques for solving the problem encompass a self-position estimating device disclosed in Patent Literature 1. According to the self-position estimating device disclosed in Patent Literature 1, landmarks such as a sign, a traffic signal, a telegraph pole, and the like provided on a roadside are designated as landmarks which may be moved, and reliability levels of the respective designated landmarks are calculated. In a case where the self-position estimating device estimates a self-position, landmarks having higher reliability levels are given influences greater than those given to landmarks having lower reliability levels. This allows the self-position estimating device to stably estimate a self-position even in an environment in which there is/are a landmark(s) having a low reliability level(s).